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2018-03-16Merge tag 'for-4.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds4-15/+15
Pull btrfs fixes from David Sterba: "There's an important revert in this pull request that needs to go to stable as it causes a corruption on big endian machines. The other fix is for FIEMAP incorrectly reporting shared extents before a sync and one fix for a crash in raid56. So far we got only one report about the BE corruption, the stable kernels were out for like a week, so hopefully the scope of the damage is low" * tag 'for-4.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Revert "btrfs: use proper endianness accessors for super_copy" btrfs: add missing initialization in btrfs_check_shared btrfs: Fix NULL pointer exception in find_bio_stripe
2018-03-16Revert "btrfs: use proper endianness accessors for super_copy"David Sterba2-15/+13
This reverts commit 3c181c12c431fe33b669410d663beb9cceefcd1b. The offending patch was merged in 4.16-rc4 and was promptly applied to stable kernels 4.14.25 and 4.15.8. The patch causes a corruption in several superblock items on big-endian machines because of messed up endianity conversions. The damage is manually repairable. A filesystem cannot be mounted again after it has been unmounted once. We do a full revert and not a fixup so stable can pick that patch ASAP. Fixes: 3c181c12c431 ("btrfs: use proper endianness accessors for super_copy") Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de CC: stable@vger.kernel.org # 4.14+ Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-15Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds3-7/+21
Pull vfs fixes from Al Viro: - backport-friendly part of lock_parent() race fix - a fix for an assumption in the heurisic used by path_connected() that is not true on NFS - livelock fixes for d_alloc_parallel() * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Teach path_connected to handle nfs filesystems with multiple roots. fs: dcache: Use READ_ONCE when accessing i_dir_seq fs: dcache: Avoid livelock between d_alloc_parallel and __d_add lock_parent() needs to recheck if dentry got __dentry_kill'ed under it
2018-03-15fs: Teach path_connected to handle nfs filesystems with multiple roots.Eric W. Biederman2-2/+5
On nfsv2 and nfsv3 the nfs server can export subsets of the same filesystem and report the same filesystem identifier, so that the nfs client can know they are the same filesystem. The subsets can be from disjoint directory trees. The nfsv2 and nfsv3 filesystems provides no way to find the common root of all directory trees exported form the server with the same filesystem identifier. The practical result is that in struct super s_root for nfs s_root is not necessarily the root of the filesystem. The nfs mount code sets s_root to the root of the first subset of the nfs filesystem that the kernel mounts. This effects the dcache invalidation code in generic_shutdown_super currently called shrunk_dcache_for_umount and that code for years has gone through an additional list of dentries that might be dentry trees that need to be freed to accomodate nfs. When I wrote path_connected I did not realize nfs was so special, and it's hueristic for avoiding calling is_subdir can fail. The practical case where this fails is when there is a move of a directory from the subtree exposed by one nfs mount to the subtree exposed by another nfs mount. This move can happen either locally or remotely. With the remote case requiring that the move directory be cached before the move and that after the move someone walks the path to where the move directory now exists and in so doing causes the already cached directory to be moved in the dcache through the magic of d_splice_alias. If someone whose working directory is in the move directory or a subdirectory and now starts calling .. from the initial mount of nfs (where s_root == mnt_root), then path_connected as a heuristic will not bother with the is_subdir check. As s_root really is not the root of the nfs filesystem this heuristic is wrong, and the path may actually not be connected and path_connected can fail. The is_subdir function might be cheap enough that we can call it unconditionally. Verifying that will take some benchmarking and the result may not be the same on all kernels this fix needs to be backported to. So I am avoiding that for now. Filesystems with snapshots such as nilfs and btrfs do something similar. But as the directory tree of the snapshots are disjoint from one another and from the main directory tree rename won't move things between them and this problem will not occur. Cc: stable@vger.kernel.org Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Fixes: 397d425dc26d ("vfs: Test for and handle paths that are unreachable from their mnt_root") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-14btrfs: add missing initialization in btrfs_check_sharedEdmund Nadolski1-0/+1
This patch addresses an issue that causes fiemap to falsely report a shared extent. The test case is as follows: xfs_io -f -d -c "pwrite -b 16k 0 64k" -c "fiemap -v" /media/scratch/file5 sync xfs_io -c "fiemap -v" /media/scratch/file5 which gives the resulting output: wrote 65536/65536 bytes at offset 0 64 KiB, 4 ops; 0.0000 sec (121.359 MiB/sec and 7766.9903 ops/sec) /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x2001 /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 This is because btrfs_check_shared calls find_parent_nodes repeatedly in a loop, passing a share_check struct to report the count of shared extent. But btrfs_check_shared does not re-initialize the count value to zero for subsequent calls from the loop, resulting in a false share count value. This is a regressive behavior from 4.13. With proper re-initialization the test result is as follows: wrote 65536/65536 bytes at offset 0 64 KiB, 4 ops; 0.0000 sec (110.035 MiB/sec and 7042.2535 ops/sec) /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 /media/scratch/file5: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..127]: 24576..24703 128 0x1 which corrects the regression. Fixes: 3ec4d3238ab ("btrfs: allow backref search checks for shared extents") Signed-off-by: Edmund Nadolski <enadolski@suse.com> [ add text from cover letter to changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-14btrfs: Fix NULL pointer exception in find_bio_stripeDmitriy Gorokh1-0/+1
On detaching of a disk which is a part of a RAID6 filesystem, the following kernel OOPS may happen: [63122.680461] BTRFS error (device sdo): bdev /dev/sdo errs: wr 0, rd 0, flush 1, corrupt 0, gen 0 [63122.719584] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo [63122.719587] BTRFS error (device sdo): bdev /dev/sdo errs: wr 1, rd 0, flush 1, corrupt 0, gen 0 [63122.803516] BTRFS warning (device sdo): lost page write due to IO error on /dev/sdo [63122.803519] BTRFS error (device sdo): bdev /dev/sdo errs: wr 2, rd 0, flush 1, corrupt 0, gen 0 [63122.863902] BTRFS critical (device sdo): fatal error on device /dev/sdo [63122.935338] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [63122.946554] IP: fail_bio_stripe+0x58/0xa0 [btrfs] [63122.958185] PGD 9ecda067 P4D 9ecda067 PUD b2b37067 PMD 0 [63122.971202] Oops: 0000 [#1] SMP [63123.006760] CPU: 0 PID: 3979 Comm: kworker/u8:9 Tainted: G W 4.14.2-16-scst34x+ #8 [63123.007091] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [63123.007402] Workqueue: btrfs-worker btrfs_worker_helper [btrfs] [63123.007595] task: ffff880036ea4040 task.stack: ffffc90006384000 [63123.007796] RIP: 0010:fail_bio_stripe+0x58/0xa0 [btrfs] [63123.007968] RSP: 0018:ffffc90006387ad8 EFLAGS: 00010287 [63123.008140] RAX: 0000000000000002 RBX: ffff88004beaa0b8 RCX: ffff8800b2bd5690 [63123.008359] RDX: 0000000000000000 RSI: ffff88007bb43500 RDI: ffff88004beaa000 [63123.008621] RBP: ffffc90006387ae8 R08: 0000000099100000 R09: ffff8800b2bd5600 [63123.008840] R10: 0000000000000004 R11: 0000000000010000 R12: ffff88007bb43500 [63123.009059] R13: 00000000fffffffb R14: ffff880036fc5180 R15: 0000000000000004 [63123.009278] FS: 0000000000000000(0000) GS:ffff8800b7000000(0000) knlGS:0000000000000000 [63123.009564] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [63123.009748] CR2: 0000000000000080 CR3: 00000000b0866000 CR4: 00000000000406f0 [63123.009969] Call Trace: [63123.010085] raid_write_end_io+0x7e/0x80 [btrfs] [63123.010251] bio_endio+0xa1/0x120 [63123.010378] generic_make_request+0x218/0x270 [63123.010921] submit_bio+0x66/0x130 [63123.011073] finish_rmw+0x3fc/0x5b0 [btrfs] [63123.011245] full_stripe_write+0x96/0xc0 [btrfs] [63123.011428] raid56_parity_write+0x117/0x170 [btrfs] [63123.011604] btrfs_map_bio+0x2ec/0x320 [btrfs] [63123.011759] ? ___cache_free+0x1c5/0x300 [63123.011909] __btrfs_submit_bio_done+0x26/0x50 [btrfs] [63123.012087] run_one_async_done+0x9c/0xc0 [btrfs] [63123.012257] normal_work_helper+0x19e/0x300 [btrfs] [63123.012429] btrfs_worker_helper+0x12/0x20 [btrfs] [63123.012656] process_one_work+0x14d/0x350 [63123.012888] worker_thread+0x4d/0x3a0 [63123.013026] ? _raw_spin_unlock_irqrestore+0x15/0x20 [63123.013192] kthread+0x109/0x140 [63123.013315] ? process_scheduled_works+0x40/0x40 [63123.013472] ? kthread_stop+0x110/0x110 [63123.013610] ret_from_fork+0x25/0x30 [63123.014469] RIP: fail_bio_stripe+0x58/0xa0 [btrfs] RSP: ffffc90006387ad8 [63123.014678] CR2: 0000000000000080 [63123.016590] ---[ end trace a295ea7259c17880 ]— This is reproducible in a cycle, where a series of writes is followed by SCSI device delete command. The test may take up to few minutes. Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index") [ no signed-off-by provided ] Author: Dmitriy Gorokh <Dmitriy.Gorokh@wdc.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-14fs/aio: Use RCU accessors for kioctx_table->table[]Tejun Heo1-10/+11
While converting ioctx index from a list to a table, db446a08c23d ("aio: convert the ioctx list to table lookup v3") missed tagging kioctx_table->table[] as an array of RCU pointers and using the appropriate RCU accessors. This introduces a small window in the lookup path where init and access may race. Mark kioctx_table->table[] with __rcu and use the approriate RCU accessors when using the field. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jann Horn <jannh@google.com> Fixes: db446a08c23d ("aio: convert the ioctx list to table lookup v3") Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org # v3.12+
2018-03-14fs/aio: Add explicit RCU grace period when freeing kioctxTejun Heo1-4/+19
While fixing refcounting, e34ecee2ae79 ("aio: Fix a trinity splat") incorrectly removed explicit RCU grace period before freeing kioctx. The intention seems to be depending on the internal RCU grace periods of percpu_ref; however, percpu_ref uses a different flavor of RCU, sched-RCU. This can lead to kioctx being freed while RCU read protected dereferences are still in progress. Fix it by updating free_ioctx() to go through call_rcu() explicitly. v2: Comment added to explain double bouncing. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jann Horn <jannh@google.com> Fixes: e34ecee2ae79 ("aio: Fix a trinity splat") Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org # v3.13+
2018-03-12Merge tag 'nfs-for-4.16-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds3-44/+54
Pull NFS client bugfixes from Trond Myklebust: "Hightlights include the following stable fixes: - NFS: Fix an incorrect type in struct nfs_direct_req - pNFS: Prevent the layout header refcount going to zero in pnfs_roc() - NFS: Fix unstable write completion" * tag 'nfs-for-4.16-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFS: Fix unstable write completion pNFS: Prevent the layout header refcount going to zero in pnfs_roc() NFS: Fix an incorrect type in struct nfs_direct_req
2018-03-09Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfsLinus Torvalds6-68/+228
Pull overlayfs fixes from Miklos Szeredi: "This fixes a corner case for NFS exporting (introduced in this cycle) as well as fixing miscellaneous bugs" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: update Kconfig texts ovl: redirect_dir=nofollow should not follow redirect for opaque lower ovl: fix ptr_ret.cocci warnings ovl: check ERR_PTR() return value from ovl_lookup_real() ovl: check lower ancestry on encode of lower dir file handle ovl: hash non-dir by lower inode for fsnotify
2018-03-09Merge tag 'xfs-4.16-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds1-12/+30
Pull xfs fixes from Darrick Wong: - Fix some iomap locking problems - Don't allocate cow blocks when we're zeroing file data * tag 'xfs-4.16-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: don't block on the ilock for RWF_NOWAIT xfs: don't start out with the exclusive ilock for direct I/O xfs: don't allocate COW blocks for zeroing holes or unwritten extents
2018-03-08NFS: Fix unstable write completionTrond Myklebust1-40/+43
We do want to respect the FLUSH_SYNC argument to nfs_commit_inode() to ensure that all outstanding COMMIT requests to the inode in question are complete. Currently we may exit early from both nfs_commit_inode() and nfs_write_inode() even if there are COMMIT requests in flight, or unstable writes on the commit list. In order to get the right semantics w.r.t. sync_inode(), we don't need to have nfs_commit_inode() reset the inode dirty flags when called from nfs_wb_page() and/or nfs_wb_all(). We just need to ensure that nfs_write_inode() leaves them in the right state if there are outstanding commits, or stable pages. Reported-by: Scott Mayhew <smayhew@redhat.com> Fixes: dc4fd9ab01ab ("nfs: don't wait on commit in nfs_commit_inode()...") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-03-08pNFS: Prevent the layout header refcount going to zero in pnfs_roc()Trond Myklebust1-3/+10
Ensure that we hold a reference to the layout header when processing the pNFS return-on-close so that the refcount value does not inadvertently go to zero. Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org # v4.10+ Tested-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
2018-03-08NFS: Fix an incorrect type in struct nfs_direct_reqTrond Myklebust1-1/+1
The start offset needs to be of type loff_t. Fixed: 5fadeb47dcc5c ("nfs: count DIO good bytes correctly with mirroring") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-03-07gfs2: Fixes to "Implement iomap for block_map" (2)Andreas Gruenbacher1-3/+0
It turns out that commit 3229c18c0d6b2 'Fixes to "Implement iomap for block_map"' introduced another bug in gfs2_iomap_begin that can cause gfs2_block_map to set bh->b_size of an actual buffer to 0. This can lead to arbitrary incorrect behavior including crashes or disk corruption. Revert the incorrect part of that commit. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2018-03-07ovl: update Kconfig textsMiklos Szeredi1-0/+14
Add some hints about overlayfs kernel config options. Enabling NFS export by default is especially recommended against, as it incurs a performance penalty even if the filesystem is not actually exported. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-04Merge tag 'for-4.16-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds10-47/+191
Pull btrfs fixes from David Sterba: - when NR_CPUS is large, a SRCU structure can significantly inflate size of the main filesystem structure that would not be possible to allocate by kmalloc, so the kvalloc fallback is used - improved error handling - fix endiannes when printing some filesystem attributes via sysfs, this is could happen when a filesystem is moved between different endianity hosts - send fixes: the NO_HOLE mode should not send a write operation for a file hole - fix log replay for for special files followed by file hardlinks - fix log replay failure after unlink and link combination - fix max chunk size calculation for DUP allocation * tag 'for-4.16-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: fix log replay failure after unlink and link combination Btrfs: fix log replay failure after linking special file and fsync Btrfs: send, fix issuing write op when processing hole in no data mode btrfs: use proper endianness accessors for super_copy btrfs: alloc_chunk: fix DUP stripe size handling btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_cluster btrfs: handle failure of add_pending_csums btrfs: use kvzalloc to allocate btrfs_fs_info
2018-03-02Merge tag 'ceph-for-4.16-rc4' of git://github.com/ceph/ceph-clientLinus Torvalds4-38/+45
Pull ceph fixes from Ilya Dryomov: "A cap handling fix from Zhi that ensures that metadata writeback isn't delayed and three error path memory leak fixups from Chengguang" * tag 'ceph-for-4.16-rc4' of git://github.com/ceph/ceph-client: ceph: fix potential memory leak in init_caches() ceph: fix dentry leak when failing to init debugfs libceph, ceph: avoid memory leak when specifying same option several times ceph: flush dirty caps of unlinked inode ASAP
2018-03-02Merge tag 'for-linus-20180302' of git://git.kernel.dk/linux-blockLinus Torvalds2-19/+33
Pull block fixes from Jens Axboe: "A collection of fixes for this series. This is a little larger than usual at this time, but that's mainly because I was out on vacation last week. Nothing in here is major in any way, it's just two weeks of fixes. This contains: - NVMe pull from Keith, with a set of fixes from the usual suspects. - mq-deadline zone unlock fix from Damien, fixing an issue with the SMR zone locking added for 4.16. - two bcache fixes sent in by Michael, with changes from Coly and Tang. - comment typo fix from Eric for blktrace. - return-value error handling fix for nbd, from Gustavo. - fix a direct-io case where we don't defer to a completion handler, making us sleep from IRQ device completion. From Jan. - a small series from Jan fixing up holes around handling of bdev references. - small set of regression fixes from Jiufei, mostly fixing problems around the gendisk pointer -> partition index change. - regression fix from Ming, fixing a boundary issue with the discard page cache invalidation. - two-patch series from Ming, fixing both a core blk-mq-sched and kyber issue around token freeing on a requeue condition" * tag 'for-linus-20180302' of git://git.kernel.dk/linux-block: (24 commits) block: fix a typo block: display the correct diskname for bio block: fix the count of PGPGOUT for WRITE_SAME mq-deadline: Make sure to always unlock zones nvmet: fix PSDT field check in command format nvme-multipath: fix sysfs dangerously created links nbd: fix return value in error handling path bcache: fix kcrashes with fio in RAID5 backend dev bcache: correct flash only vols (check all uuids) blktrace_api.h: fix comment for struct blk_user_trace_setup blockdev: Avoid two active bdev inodes for one device genhd: Fix BUG in blkdev_open() genhd: Fix use after free in __blkdev_get() genhd: Add helper put_disk_and_module() genhd: Rename get_disk() to get_disk_and_module() genhd: Fix leaked module reference for NVME devices direct-io: Fix sleep in atomic due to sync AIO nvme-pci: Fix nvme queue cleanup if IRQ setup fails block: kyber: fix domain token leak during requeue blk-mq: don't call io sched's .requeue_request when requeueing rq to ->dispatch ...
2018-03-01xfs: don't block on the ilock for RWF_NOWAITChristoph Hellwig1-8/+19
Fix xfs_file_iomap_begin to trylock the ilock if IOMAP_NOWAIT is passed, so that we don't block io_submit callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-01xfs: don't start out with the exclusive ilock for direct I/OChristoph Hellwig1-4/+2
There is no reason to take the ilock exclusively at the start of xfs_file_iomap_begin for direct I/O, given that it will be demoted just before calling xfs_iomap_write_direct anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-01xfs: don't allocate COW blocks for zeroing holes or unwritten extentsChristoph Hellwig1-1/+10
The iomap zeroing interface is smart enough to skip zeroing holes or unwritten extents. Don't subvert this logic for reflink files. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-01ceph: fix potential memory leak in init_caches()Chengguang Xu1-3/+6
There is lack of cache destroy operation for ceph_file_cachep when failing from fscache register. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-03-01Btrfs: fix log replay failure after unlink and link combinationFilipe Manana3-22/+139
If we have a file with 2 (or more) hard links in the same directory, remove one of the hard links, create a new file (or link an existing file) in the same directory with the name of the removed hard link, and then finally fsync the new file, we end up with a log that fails to replay, causing a mount failure. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/testdir $ touch /mnt/testdir/foo $ ln /mnt/testdir/foo /mnt/testdir/bar $ sync $ unlink /mnt/testdir/bar $ touch /mnt/testdir/bar $ xfs_io -c "fsync" /mnt/testdir/bar <power failure> $ mount /dev/sdb /mnt mount: mount(2) failed: /mnt: No such file or directory When replaying the log, for that example, we also see the following in dmesg/syslog: [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257 [71813.674204] ------------[ cut here ]------------ [71813.675694] BTRFS: Transaction aborted (error -2) [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs] [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G W 4.15.0-rc9-btrfs-next-56+ #1 [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs] [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286 [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001 [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001 [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8 [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101 [71813.679669] FS: 00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000 [71813.679669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0 [71813.679669] Call Trace: [71813.679669] btrfs_unlink_inode+0x17/0x41 [btrfs] [71813.679669] drop_one_dir_item+0xfa/0x131 [btrfs] [71813.679669] add_inode_ref+0x71e/0x851 [btrfs] [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] ? replay_one_buffer+0x53/0x53a [btrfs] [71813.679669] replay_one_buffer+0x4a4/0x53a [btrfs] [71813.679669] ? rcu_read_unlock+0x3a/0x57 [71813.679669] ? __lock_is_held+0x39/0x71 [71813.679669] walk_up_log_tree+0x101/0x1d2 [btrfs] [71813.679669] walk_log_tree+0xad/0x188 [btrfs] [71813.679669] btrfs_recover_log_trees+0x1fa/0x31e [btrfs] [71813.679669] ? replay_one_extent+0x544/0x544 [btrfs] [71813.679669] open_ctree+0x1cf6/0x2209 [btrfs] [71813.679669] btrfs_mount_root+0x368/0x482 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] btrfs_mount+0x13e/0x772 [btrfs] [71813.679669] ? trace_hardirqs_on_caller+0x14c/0x1a6 [71813.679669] ? __lockdep_init_map+0x176/0x1c2 [71813.679669] ? mount_fs+0x64/0x10b [71813.679669] mount_fs+0x64/0x10b [71813.679669] vfs_kern_mount+0x68/0xce [71813.679669] do_mount+0x6e5/0x973 [71813.679669] ? memdup_user+0x3e/0x5c [71813.679669] SyS_mount+0x72/0x98 [71813.679669] entry_SYSCALL_64_fastpath+0x1e/0x8b [71813.679669] RIP: 0033:0x7f7cedf150ba [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206 [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c [71813.679669] ---[ end trace 83bd473fc5b4663b ]--- [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree) [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30 [71814.128078] BTRFS error (device dm-0): open_ctree failed This happens because the log has inode reference items for both inode 258 (the first file we created) and inode 259 (the second file created), and when processing the reference item for inode 258, we replace the corresponding item in the subvolume tree (which has two names, "foo" and "bar") witht he one in the log (which only has one name, "foo") without removing the corresponding dir index keys from the parent directory. Later, when processing the inode reference item for inode 259, which has a name of "bar" associated to it, we notice that dir index entries exist for that name and for a different inode, so we attempt to unlink that name, which fails because the inode reference item for inode 258 no longer has the name "bar" associated to it, making a call to btrfs_unlink_inode() fail with a -ENOENT error. Fix this by unlinking all the names in an inode reference item from a subvolume tree that are not present in the inode reference item found in the log tree, before overwriting it with the item from the log tree. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01Btrfs: fix log replay failure after linking special file and fsyncFilipe Manana1-1/+1
If in the same transaction we rename a special file (fifo, character/block device or symbolic link), create a hard link for it having its old name then sync the log, we will end up with a log that can not be replayed and at when attempting to replay it, an EEXIST error is returned and mounting the filesystem fails. Example scenario: $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt $ mkdir /mnt/testdir $ mkfifo /mnt/testdir/foo # Make sure everything done so far is durably persisted. $ sync # Create some unrelated file and fsync it, this is just to create a log # tree. The file must be in the same directory as our special file. $ touch /mnt/testdir/f1 $ xfs_io -c "fsync" /mnt/testdir/f1 # Rename our special file and then create a hard link with its old name. $ mv /mnt/testdir/foo /mnt/testdir/bar $ ln /mnt/testdir/bar /mnt/testdir/foo # Create some other unrelated file and fsync it, this is just to persist # the log tree which was modified by the previous rename and link # operations. Alternatively we could have modified file f1 and fsync it. $ touch /mnt/f2 $ xfs_io -c "fsync" /mnt/f2 <power failure> $ mount /dev/sdc /mnt mount: mount /dev/sdc on /mnt failed: File exists This happens because when both the log tree and the subvolume's tree have an entry in the directory "testdir" with the same name, that is, there is one key (258 INODE_REF 257) in the subvolume tree and another one in the log tree (where 258 is the inode number of our special file and 257 is the inode for directory "testdir"). Only the data of those two keys differs, in the subvolume tree the index field for inode reference has a value of 3 while the log tree it has a value of 5. Because the same key exists in both trees, but have different index, the log replay fails with an -EEXIST error when attempting to replay the inode reference from the log tree. Fix this by setting the last_unlink_trans field of the inode (our special file) to the current transaction id when a hard link is created, as this forces logging the parent directory inode, solving the conflict at log replay time. A new generic test case for fstests was also submitted. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01Btrfs: send, fix issuing write op when processing hole in no data modeFilipe Manana1-0/+3
When doing an incremental send of a filesystem with the no-holes feature enabled, we end up issuing a write operation when using the no data mode send flag, instead of issuing an update extent operation. Fix this by issuing the update extent operation instead. Trivial reproducer: $ mkfs.btrfs -f -O no-holes /dev/sdc $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdc /mnt/sdc $ mount /dev/sdd /mnt/sdd $ xfs_io -f -c "pwrite -S 0xab 0 32K" /mnt/sdc/foobar $ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap1 $ xfs_io -c "fpunch 8K 8K" /mnt/sdc/foobar $ btrfs subvolume snapshot -r /mnt/sdc /mnt/sdc/snap2 $ btrfs send /mnt/sdc/snap1 | btrfs receive /mnt/sdd $ btrfs send --no-data -p /mnt/sdc/snap1 /mnt/sdc/snap2 \ | btrfs receive -vv /mnt/sdd Before this change the output of the second receive command is: receiving snapshot snap2 uuid=f6922049-8c22-e544-9ff9-fc6755918447... utimes write foobar, offset 8192, len 8192 utimes foobar BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=f6922049-8c22-e544-9ff9-... After this change it is: receiving snapshot snap2 uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64... utimes update_extent foobar: offset=8192, len=8192 utimes foobar BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=564d36a3-ebc8-7343-aec9-bf6fda278e64... Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: use proper endianness accessors for super_copyAnand Jain2-13/+15
The fs_info::super_copy is a byte copy of the on-disk structure and all members must use the accessor macros/functions to obtain the right value. This was missing in update_super_roots and in sysfs readers. Moving between opposite endianness hosts will report bogus numbers in sysfs, and mount may fail as the root will not be restored correctly. If the filesystem is always used on a same endian host, this will not be a problem. Fix this by using the btrfs_set_super...() functions to set fs_info::super_copy values, and for the sysfs, use the cached fs_info::nodesize/sectorsize values. CC: stable@vger.kernel.org Fixes: df93589a17378 ("btrfs: export more from FS_INFO to sysfs") Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: alloc_chunk: fix DUP stripe size handlingHans van Kranenburg1-5/+6
In case of using DUP, we search for enough unallocated disk space on a device to hold two stripes. The devices_info[ndevs-1].max_avail that holds the amount of unallocated space found is directly assigned to stripe_size, while it's actually twice the stripe size. Later on in the code, an unconditional division of stripe_size by dev_stripes corrects the value, but in the meantime there's a check to see if the stripe_size does not exceed max_chunk_size. Since during this check stripe_size is twice the amount as intended, the check will reduce the stripe_size to max_chunk_size if the actual correct to be used stripe_size is more than half the amount of max_chunk_size. The unconditional division later tries to correct stripe_size, but will actually make sure we can't allocate more than half the max_chunk_size. Fix this by moving the division by dev_stripes before the max chunk size check, so it always contains the right value, instead of putting a duct tape division in further on to get it fixed again. Since in all other cases than DUP, dev_stripes is 1, this change only affects DUP. Other attempts in the past were made to fix this: * 37db63a400 "Btrfs: fix max chunk size check in chunk allocator" tried to fix the same problem, but still resulted in part of the code acting on a wrongly doubled stripe_size value. * 86db25785a "Btrfs: fix max chunk size on raid5/6" unintentionally broke this fix again. The real problem was already introduced with the rest of the code in 73c5de0051. The user visible result however will be that the max chunk size for DUP will suddenly double, while it's actually acting according to the limits in the code again like it was 5 years ago. Reported-by: Naohiro Aota <naohiro.aota@wdc.com> Link: https://www.spinics.net/lists/linux-btrfs/msg69752.html Fixes: 73c5de0051 ("btrfs: quasi-round-robin for chunk allocation") Fixes: 86db25785a ("Btrfs: fix max chunk size on raid5/6") Signed-off-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Reviewed-by: David Sterba <dsterba@suse.com> [ update comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: Handle btrfs_set_extent_delalloc failure in relocate_file_extent_clusterNikolay Borisov1-2/+16
Essentially duplicate the error handling from the above block which handles the !PageUptodate(page) case and additionally clear EXTENT_BOUNDARY. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: handle failure of add_pending_csumsNikolay Borisov1-2/+9
add_pending_csums was added as part of the new data=ordered implementation in e6dcd2dc9c48 ("Btrfs: New data=ordered implementation"). Even back then it called the btrfs_csum_file_blocks which can fail but it never bothered handling the failure. In ENOMEM situation this could lead to the filesystem failing to write the checksums for a particular extent and not detect this. On read this could lead to the filesystem erroring out due to crc mismatch. Fix it by propagating failure from add_pending_csums and handling them. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-01btrfs: use kvzalloc to allocate btrfs_fs_infoJeff Mahoney2-2/+2
The srcu_struct in btrfs_fs_info scales in size with NR_CPUS. On kernels built with NR_CPUS=8192, this can result in kmalloc failures that prevent mounting. There is work in progress to try to resolve this for every user of srcu_struct but using kvzalloc will work around the failures until that is complete. As an example with NR_CPUS=512 on x86_64: the overall size of subvol_srcu is 3460 bytes, fs_info is 6496. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-28Merge tag 'xfs-4.16-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds4-5/+13
Pull xfs fixes from Darrick Wong: - fix some compiler warnings - fix block reservations for transactions created during log recovery - fix resource leaks when respecifying mount options * tag 'xfs-4.16-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: fix potential memory leak in mount option parsing xfs: reserve blocks for refcount / rmap log item recovery xfs: use memset to initialize xfs_scrub_agfl_info
2018-02-26xfs: fix potential memory leak in mount option parsingChengguang Xu1-0/+2
When specifying string type mount option (e.g., logdev) several times in a mount, current option parsing may cause memory leak. Hence, call kfree for previous one in this case. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-02-26blockdev: Avoid two active bdev inodes for one deviceJan Kara1-2/+23
When blkdev_open() races with device removal and creation it can happen that unhashed bdev inode gets associated with newly created gendisk like: CPU0 CPU1 blkdev_open() bdev = bd_acquire() del_gendisk() bdev_unhash_inode(bdev); remove device create new device with the same number __blkdev_get() disk = get_gendisk() - gets reference to gendisk of the new device Now another blkdev_open() will not find original 'bdev' as it got unhashed, create a new one and associate it with the same 'disk' at which point problems start as we have two independent page caches for one device. Fix the problem by verifying that the bdev inode didn't get unhashed before we acquired gendisk reference. That way we make sure gendisk can get associated only with visible bdev inodes. Tested-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Fix use after free in __blkdev_get()Jan Kara1-2/+5
When two blkdev_open() calls race with device removal and recreation, __blkdev_get() can use looked up gendisk after it is freed: CPU0 CPU1 CPU2 del_gendisk(disk); bdev_unhash_inode(inode); blkdev_open() blkdev_open() bdev = bd_acquire(inode); - creates and returns new inode bdev = bd_acquire(inode); - returns the same inode __blkdev_get(devt) __blkdev_get(devt) disk = get_gendisk(devt); - got structure of device going away <finish device removal> <new device gets created under the same device number> disk = get_gendisk(devt); - got new device structure if (!bdev->bd_openers) { does the first open } if (!bdev->bd_openers) - false } else { put_disk_and_module(disk) - remember this was old device - this was last ref and disk is now freed } disk_unblock_events(disk); -> oops Fix the problem by making sure we drop reference to disk in __blkdev_get() only after we are really done with it. Reported-by: Hou Tao <houtao1@huawei.com> Tested-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Add helper put_disk_and_module()Jan Kara1-14/+5
Add a proper counterpart to get_disk_and_module() - put_disk_and_module(). Currently it is opencoded in several places. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26direct-io: Fix sleep in atomic due to sync AIOJan Kara1-2/+1
Commit e864f39569f4 "fs: add RWF_DSYNC aand RWF_SYNC" added additional way for direct IO to become synchronous and thus trigger fsync from the IO completion handler. Then commit 9830f4be159b "fs: Use RWF_* flags for AIO operations" allowed these flags to be set for AIO as well. However that commit forgot to update the condition checking whether the IO completion handling should be defered to a workqueue and thus AIO DIO with RWF_[D]SYNC set will call fsync() from IRQ context resulting in sleep in atomic. Fix the problem by checking directly iocb flags (the same way as it is done in dio_complete()) instead of checking all conditions that could lead to IO being synchronous. CC: Christoph Hellwig <hch@lst.de> CC: Goldwyn Rodrigues <rgoldwyn@suse.com> CC: stable@vger.kernel.org Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Fixes: 9830f4be159b29399d107bffb99e0132bc5aedd4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26ovl: redirect_dir=nofollow should not follow redirect for opaque lowerVivek Goyal1-3/+3
redirect_dir=nofollow should not follow a redirect. But in a specific configuration it can still follow it. For example try this. $ mkdir -p lower0 lower1/foo upper work merged $ touch lower1/foo/lower-file.txt $ setfattr -n "trusted.overlay.opaque" -v "y" lower1/foo $ mount -t overlay -o lowerdir=lower1:lower0,workdir=work,upperdir=upper,redirect_dir=on none merged $ cd merged $ mv foo foo-renamed $ umount merged # mount again. This time with redirect_dir=nofollow $ mount -t overlay -o lowerdir=lower1:lower0,workdir=work,upperdir=upper,redirect_dir=nofollow none merged $ ls merged/foo-renamed/ # This lists lower-file.txt, while it should not have. Basically, we are doing redirect check after we check for d.stop. And if this is not last lower, and we find an opaque lower, d.stop will be set. ovl_lookup_single() if (!d->last && ovl_is_opaquedir(this)) { d->stop = d->opaque = true; goto out; } To fix this, first check redirect is allowed. And after that check if d.stop has been set or not. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Fixes: 438c84c2f0c7 ("ovl: don't follow redirects if redirect_dir=off") Cc: <stable@vger.kernel.org> #v4.15 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-02-26ceph: fix dentry leak when failing to init debugfsChengguang Xu1-11/+5
When failing from ceph_fs_debugfs_init() in ceph_real_mount(), there is lack of dput of root_dentry and it causes slab errors, so change the calling order of ceph_fs_debugfs_init() and open_root_dentry() and do some cleanups to avoid this issue. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-02-26libceph, ceph: avoid memory leak when specifying same option several timesChengguang Xu1-0/+2
When parsing string option, in order to avoid memory leak we need to carefully free it first in case of specifying same option several times. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-02-26ceph: flush dirty caps of unlinked inode ASAPZhi Zhang3-24/+32
Client should release unlinked inode from its cache ASAP. But client can't release inode with dirty caps. Link: http://tracker.ceph.com/issues/22886 Signed-off-by: Zhi Zhang <zhang.david2011@gmail.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2018-02-26ovl: fix ptr_ret.cocci warningsFengguang Wu1-1/+1
fs/overlayfs/export.c:459:10-16: WARNING: PTR_ERR_OR_ZERO can be used Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR Generated by: scripts/coccinelle/api/ptr_ret.cocci Fixes: 4b91c30a5a19 ("ovl: lookup connected ancestor of dir in inode cache") CC: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-02-25Merge tag 'nfs-for-4.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds3-11/+11
Pull NFS client bugfixes from Trond Myklebust: - fix a broken cast in nfs4_callback_recallany() - fix an Oops during NFSv4 migration events - make struct nlmclnt_fl_close_lock_ops static * tag 'nfs-for-4.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFS: make struct nlmclnt_fl_close_lock_ops static nfs: system crashes after NFS4ERR_MOVED recovery NFSv4: Fix broken cast in nfs4_callback_recallany()
2018-02-25fs: dcache: Use READ_ONCE when accessing i_dir_seqWill Deacon1-1/+1
i_dir_seq is subject to concurrent modification by a cmpxchg or store-release operation, so ensure that the relaxed access in d_alloc_parallel uses READ_ONCE. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-25fs: dcache: Avoid livelock between d_alloc_parallel and __d_addWill Deacon1-1/+7
If d_alloc_parallel runs concurrently with __d_add, it is possible for d_alloc_parallel to continuously retry whilst i_dir_seq has been incremented to an odd value by __d_add: CPU0: __d_add n = start_dir_add(dir); cmpxchg(&dir->i_dir_seq, n, n + 1) == n CPU1: d_alloc_parallel retry: seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1; hlist_bl_lock(b); bit_spin_lock(0, (unsigned long *)b); // Always succeeds CPU0: __d_lookup_done(dentry) hlist_bl_lock bit_spin_lock(0, (unsigned long *)b); // Never succeeds CPU1: if (unlikely(parent->d_inode->i_dir_seq != seq)) { hlist_bl_unlock(b); goto retry; } Since the simple bit_spin_lock used to implement hlist_bl_lock does not provide any fairness guarantees, then CPU1 can starve CPU0 of the lock and prevent it from reaching end_dir_add(dir), therefore CPU1 cannot exit its retry loop because the sequence number always has the bottom bit set. This patch resolves the livelock by not taking hlist_bl_lock in d_alloc_parallel if the sequence counter is odd, since any subsequent masked comparison with i_dir_seq will fail anyway. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Reported-by: Naresh Madhusudana <naresh.madhusudana@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-23lock_parent() needs to recheck if dentry got __dentry_kill'ed under itAl Viro1-3/+8
In case when dentry passed to lock_parent() is protected from freeing only by the fact that it's on a shrink list and trylock of parent fails, we could get hit by __dentry_kill() (and subsequent dentry_kill(parent)) between unlocking dentry and locking presumed parent. We need to recheck that dentry is alive once we lock both it and parent *and* postpone rcu_read_unlock() until after that point. Otherwise we could return a pointer to struct dentry that already is rcu-scheduled for freeing, with ->d_lock held on it; caller's subsequent attempt to unlock it can end up with memory corruption. Cc: stable@vger.kernel.org # 3.12+, counting backports Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-22Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespaceLinus Torvalds1-3/+12
Pull siginfo fix from Eric Biederman: "This fixes a build error that only shows up on blackfin" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: fs/signalfd: fix build error for BUS_MCEERR_AR
2018-02-22xfs: reserve blocks for refcount / rmap log item recoveryDarrick J. Wong2-4/+9
During log recovery, the per-AG reservations aren't yet set up, so log recovery has to reserve enough blocks to handle all possible btree splits. Reported-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-02-22xfs: use memset to initialize xfs_scrub_agfl_infoEric Sandeen1-1/+2
Apparently different gcc versions have competing and incompatible notions of how to initialize at declaration, so just give up and fall back to the time-tested memset(). Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-02-22fs/signalfd: fix build error for BUS_MCEERR_ARRandy Dunlap1-3/+12
Fix build error in fs/signalfd.c by using same method that is used in kernel/signal.c: separate blocks for different signal si_code values. ./fs/signalfd.c: error: 'BUS_MCEERR_AR' undeclared (first use in this function) Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>